1. Field of the Invention
The present invention relates to collapsible shelters and tents having sheet material walls supported by a collapsible frame. The present invention provides, among other things, an improved collapsible shelter or tent having a frame locking mechanism.
2. Background of the Invention
Collapsible tents, such as umbrella tents, are well known in the art. The term xe2x80x9cumbrella tentxe2x80x9d is commonly used in the trade because the frames for such tents can be erected and collapsed in much the same manner as an umbrella. Some exemplary collapsible tents are shown in, for example, U.S. Pat. No.: 5,230,358 (Forell); U.S. Pat. No. 4,945,936 (D. Surrendi); U.S. Pat. No. 4,202,363 (Watts et al.); U.S. Pat. No. 3,929,146 (Maiken); and U.S. Pat. No. 2,771,087 (Simonson).
U.S. Pat. No. 5,230,358 shows a foldable tent and frame therefor that includes a number of complex drive mechanisms to move upper and lower spiders 14 and 16, respectively, toward and away from one another to erect and collapse the tent frame. The drive mechanisms also include a locking mechanism for securing the spider assembly in an erected condition.
U.S. Pat. No. 4,945,936 shows a collapsible tent having a frame with an upper clevis member 10 and a lower clevis member 11 that are manually moved towards and away from one another, without a complex drive mechanism, to erect and collapse the tent. The ""936 tent does not contain, however, a separate locking mechanism to lock the upper and lower clevis members together. In order to assemble the tent, the tent is initially in a position like that shown in FIG. 2. The lower clevis member 11 is then forced up towards the upper clevis member 10. The structure of the tent creates a force resisting upward movement of the lower clevis member 11 towards the upper clevis member 10 until the radial brace members 28 become generally horizontal. Thereafter, the force on the lower clevis member 11 actually causes the lower clevis member 11 to move towards the upper clevis member 10. As a result, in an assembled state as shown in FIGS. 1 and 5, wherein the stop member 26 is seated within the recess 15, the tent is self-sustaining and an additional locking mechanism is not included. The ""963 patent can collapse, however, upon the application of a modest downward pressure to the top of the upper clevis member when the frame is assembled.
U.S. Pat. No. 4,202,363 shows an umbrella type collapsible shelter having an upper hub 12 and a lower hub 14 that are moved toward one another to erect the shelter. Similar to the ""936 device, when the rib members 15 move past the position perpendicular to the vertical center line of the shelter, the resultant upward force on the hub 14 due to the stress in the bowed support members 11 tends to hold the hub 14 proximate to the central hub 12 to maintain the shelter in the erected position. (See col. 4, lines 45, et seq., of the ""363 patent.) In addition, the ""363 device includes means for preventing inadvertent collapse of the shelter. In particular, the upper hub 12 includes a bore 23 and the lower hub 14 includes a bore 24 aligned with but eccentric to the bore 23. An erecting means 13 (e.g., an elongated rope or rod) extends through the bores 23 and 24. After the structure is assembled, as stated on col. 6, lines 17 et seq., xe2x80x9c[t] the second hub 14 is then rotated by about one-quarter to about three-eighths of a turn about the axis of the erecting meansxe2x80x9d which creates a binding action due to the eccentric relationship. The ""363 device, however, has a number of drawbacksxe2x80x94for example: a) the means for preventing inadvertent collapse of the hubs 12 and 14 involves hubs which rotate with respect to one another (and with respect to legs or the like attached thereto); b) the means for preventing inadvertent collapse is complex, unreliable, and can create undue stress on parts; c) the ""363 involves mounting the shelter fabric within the frame, creating undue exposure and potential damage of the frame structure and creating other deficiencies.
U.S. Pat. No. 2,771,087 shows a portable screen having a locking mechanism that locks together an upper ridge piece 12 and a lower latching block 24. The locking mechanism of the ""087 device also contains a number of drawbacks. In the ""087 device, the latching block 24 has an upper cap member 30 with a coil spring 40 that biases loop portions 40 outwardly. The ridge piece 12 includes a central bore 20 that receives the cap member 30. A flexible element 44 is used to pull the cap member 30 vertically through the bore 20 of a ridge piece 12 to lock the latching block 24 to the ridge piece 12 once the loop portions 36 are seated above the screen 54 to lock the device. The drawbacks of the ""087 device include, for example, that the locking mechanism can be: a) disadvantageously exposed to the environment; b) inconvenient since disassembly should be initiated from outside of the shelter; and c) undesirable because it involves mounting the frame outside of the screen 54 which reduces the design options of the device.
There remains a need in the art for the continued improvement of collapsible shelters and tents and, for example, for a collapsible shelter or tent having an improved means for locking a frame thereof in an assembled state.
The present invention provides a variety of features that overcome the above-noted problems and many other problems existing in the art.
A first aspect of the invention involves the provision of a collapsible shelter/tent that has an improved means for locking a frame thereof in an assembled state. In this regard, a collapsible shelter/tent can be provided that includes: a collapsible frame including: a) three or more legs pivotally connected to a first clevis; and b) three or more support bars pivotally connected with respect to the legs at an outer end of the support bars and pivotally connected to a second clevis at an inner end of the support bars; a locking mechanism for locking the first and second devises together when the shelter/tent is assembled which includes: a) a generally vertical pin extending from one of the first and second clevises, the generally vertical pin having a groove on a side thereof; b) a socket on the other of the devises having a receiving bore aligned with the generally vertical pin; c) an engaging member supported within the socket that can firmly engage the groove in the generally vertical pin after the generally vertical pin is inserted into the socket; and a plurality sheet-material walls supported on the collapsible frame.
Preferably, the collapsible shelter/tent includes biasing means for biasing the engaging member into the groove automatically upon engagement of the first and second clevises.
In one exemplary embodiment, the first clevis is above the second clevis and the generally vertical pin extends downward from the first clevis towards the second clevis. Preferably, the socket is fixed to the second clevis and includes a central bore and a widened opening having a funnel-shape receiving surface. The diameter across the widened opening having the funnel-shape receiving surface is preferably substantially greater than a diameter across the vertical pin to ensure engagement and can be, for example, more than 2 times, or even more than 2.5 times, or even more than 3 times as great.
According to another aspect of the invention, an erection device is provided that includes: an assembly pole having a slide supported thereon; the assembly pole having a tip with an engagement element; the generally vertical pin having a lower end with a corresponding engagement element for engaging the tip of the assembly pole; and the second clevis and the socket having a through-hole through which the assembly pole is insertable so that the tip of the assembly pole can be engaged with the generally vertical pin.
The present invention has a number of advantages not found in the references. A number of these advantages are discussed below. The following advantages are found in the more preferred embodiments, but are not absolutely required in every embodiment of the invention.
The present locking mechanism can be embodied substantially within a lower clevis assembly which can, for example, receive a downward protruding pin from the upper clevis member.
The present locking mechanism allows the frame to be located either inside or outside of the shelter/tent sheet-material (e.g., fabric, etc.) walls.
The present locking mechanism does not need to be exposed to the environment since, for example, the locking mechanism can be internalized within the clevis assembly, and notably substantially within the lower clevis member. The frame and locking mechanism is thus less likely to become corroded, to accumulate dirt or dust, etc., which could negatively effect the device or its operation.
The present device is also more convenient for the user because the user can unlock the device from a position within the shelter/tent.
The present invention also does not require an external element such as a chord or the like so that the present design can be mounted either inside or outside of the shelter/tent sheet-material walls.
The above and many other aspects, features and advantages of the present invention are further presented in the detailed description of the preferred embodiments of the invention which follows.